Lifting jack



June 27, 1950 P. MOENCH LIFTING JACK Filed Aug. 28, 1946 3 Sheets-Sheet 1 PAUL MOELNCH m- P. MOENCH LIFTING JACK June 27, 1950 3 Sheets-Sheet 2 Filed Aug. 2a, 1946 PRUJJ MOEN 63% Patented June 27, 1950 UNITED STATES PATENT OFFICE Accessories CorporatiomNew York,.N. Y.

Application August 28, 1946; Serial No. 693,391

This invention relates to lifting jacks and particularly to the type employed for elevating vehicles.

The invention consists of aseries of links pivotall associated together, on the principle of lazytongs or of the scissors type, and having the links connected to a base member and a load bearing member so that when the links are caused to assume an expanded or distended position theywill support a vehicle or other load.

A further object is to elevate the jack by hydraulic means, wherein links of the base and load members are. pivotally connected to cylinders, and which cylinders are caused to slide'on a shaft which guides the movement of the cylin-- ders from and toward each other indistending or contracting the linkage in elevating and-lowering a load.

The-invention consists =ofv certain novel features of constructionand combinations of parts which will be hereinafter described and set forth in the claims.

In the accompanying drawings:

Figure 1 is a View in side elevation with the jack in raised position;

Figure 2 is a view in side elevation showing the jack in a partially collapsed position;

Figure 3 is a view in top plan view of the jack when collapsed;

Figure 41s a longitudinal vertical sectional view through a cylinder, an end of the shaft, and a spacer member carried by the cylinder;

Figure 5 is a vertical sectional View of the pump.

As shown in the drawings, a shaft H) has mounted thereon at each end a cylinder l l. The cylinders are each closed by a cap [2 at their outer ends, and by a gland nut 13 at their inner ends, which nut slides on the shaft ill. Suitable packin I4 is interposed between the gland nut and a retainer plug l5 screwed to the nut [3, for forming a liquidtight fit.

At each end of the shaft It is a plug or bolt is for retaining. suitable packing or washers I! to the shaft, which packing and plug act as pistons invthe reciprocation of the cylinders on the shaft.

Mounted on the cylinders are spacer members lB-Jfi consisting preferably, of two channelshaped1nembers,.which aresoconstructed that one member. fits within the other sothat the side Walls are closed. The spacer members is are held in position by lock nuts I9, l9 screwed onto the outer cylinder wall.

The base member 20 of the jack is provided 5 Claims. (Cl. 254'-122)- with upstanding flanges 2|, 2| to each of which are pivoted'two-sets'of links 22 and'22 by means of pins or trunnio'ns v23, 23. The links of each pair cross each' other, and the upper or free: ends of these links are pivoted to the upper ends of spacer members it of the cylinders ll by pins or trunnions 24, 24 passing through the spacer members and ends of thetwospairs of links, so that a pair of links attached to the base are located on opposite sides of the respective spacer [8 by means of the pins or trunnions 28' which pass through the links and spacer members. The links are also pivotally connected to the load sup porting member 26 by-pins or trunnions 29 which pass through themembers 26". A pair of shorter links 30 are pivotally mounted to one of the? spacer members 18 by the pins or trunnions 28- and at their upper ends are connected to one of the links 21' on each side of the member 26 by a suitable pivot 32. Similarly there isa pair of links 33 connected? tothe other spacer member l8 but to'the upper portion thereof by means of the pin and these links extend downwardly and engage a link 22 extending upwardly from the base by means of pivots 34. The base member- 28 and'the loadsupporting member 26 are of greaterlength than the length of the spacer members l8 so that the links 22, 22 and 21, 21-

are spaced farther. apart on the base member 20 and. member 26 than the ends of the links arev spaced onthespacer members-l8. Thatis, the

links onthespacer members are in closer proximity from their pivot points than the. links from their pivots When connected to the members 20 and 26.

Ihe pivots 32 of the links 36 which connecteach ofthe links: 30 with its respective link 21',

are each disposed to one side of the center line of. the jack, and is on the same side of the age.

center lineas the spacer member [6 towhich the links 30 are pivoted. Likewise each of the pivots 34 which connect each of the links 33 to its respective, link .22, is disposed to one side of the center. line. of the jack and on the side while the other spacer member l8 and cylinder l l i will be elevated. The load supporting member 26 willbe disposed above the spacer member I8 assuming the lowermost position of the two spacer members. The purpose of this arrangement is to permit the load member 26 to move for wardly or laterally with respect to thebase 20, so that the jack and member 26 follows the movement of the vehicle in its lifting arc, while at the same time the jack is moved vertically to elevate the vehicle and to sustain the load carried by the jack regardless of the elevation to which the jack is subjected. During these movements of the linkage and the supporting member 26, the supporting member 26 and the base 20 always remain in parallelism, so that there is no liability of the vehicle sliding off or from the load supporting member 26.

Mounted upon the base is' a liquid pump 38 which has communication with the shaft Ill by means of a flexible hose 39. The shaft I0 is preferably made hollow so that the fluid is distributed axially of the shaft l9 into the cylinders H. The shaft I0 is provided with lateral passages 40 which communicate with the longitudinal or axial passage 4| of the shaft for delivering the oil to the cylinder between the gland nut l3 and the head of the shaft. There fore upon the delivery of the oil to the shaft, the oil will enter the cylinder and the pressure will be'exerted againstthe ends of the shaft Ill causing the cylinders to move toward each other thereby causing the linkage Z2, 22' and 21, 21' to be extended and thereby elevate the platform 26 to whatever height is desired. When it is desired to lower or collapse the jack, a releasing valv'e 4501? the pump is operated for allowing the fluid to travel through the passage 45 of the pump and to the main delivery passage 41 and thence to a reservoir 48. The oil is drawn from the reservoirbyoperating the piston 50 by the hand lever 52. v

A jack of this character may be fitted beneath the axle of a very low slung car as it is capable of being collapsed at least 4 /2 inches in height and may be elevated to a height of 14 inches. 7

Of course these measurements may be varied and the foregoing is merely a statement of one of the possibilities for a, jack of this character. With this construction, the shaft Ill acts as a support for the cylinders II as well as a guide in their movement from and toward each other as well as during any arcing movement that the cylinders may take in the raising and lowering of the jack and as the load bearing member 26 is moved forwardly with respect to the base in following the arcing movement of the vehicle as it is lifted.

I claim:

,1. In a lifting device, the combination of a guide shaft having opposed cylinders'mounted thereon for movement from and toward each other, a base member and a load supporting member disposed on opposite sides of said shaft, two sets of crossed links pivotally connected to said base and each set of links extending to and pivotally connected to one of said cylinders and a second two sets of crossed links pivotally connected to said load supporting member and each of said second set of links extending to and connected to each of said cylinders, and means for delivering fluid to said cylinders for effecting relative movement of said cylinders toward each other with respect to said shaft to extend said crossed links for elevating the load member with respect to the base member.

2. In a lifting device, the combination with a shaft having cylinders mounted thereon for movement from and toward each other on said shaft, spacer members mounted on said cylinders, a base member and a load supporting member, two sets of links pivotally connected to said base member and each set of links connected to a spacer member, a second two sets of links pivotally connected to said load supporting member and each of said second set of links pivotally connected to a spacer member below the pivot points of the links of said base member and means for delivering fluid to said cylinders for effecting relative movement of said cylinders with respect to said shaft for extending said links in elevating the load supporting member.

3. In a lifting device, the combination of a guide shaft, cylinders mounted on said shaft and having longitudinal sliding movement with respect to said shaft, a base member and a load supporting member disposed on opposite sides of said shaft, links pivotally connected to said base member, one of said links pivotally connected to one of said cylinders and said other link -pivotally connected to said other cylinder, a second set of links pivotally connected to said load supporting member, one of said links of said second set pivotally connected to one of said cylinders and said other link of said second set pivotally conected to said other cylinder, and means for delivering fluid to said cylinders for effecting relative movement of said cylinders toward each other with respect to said shaft to extend said links in elevating said load supporting members.

4. In a lifting device, the combination of a hollow guide shaft having pistons at the ends thereof, cylinders mounted on said shaft and cooperating with said pistons, said cylinders having relative longitudinal sliding movement from and toward each other with respect to said shaft, a base member and a load supporting member disposed on opposite sides of said shaft, links pivotally connected to said base member, one of said links pivotally connected to one of said cylinders and said other link pivotally connected to said other cylinder, a second set of links pivotally connected to said load supporting member, one of said links of said second set pivotally connected to one of said cylinders and said other link of said second set pivotally connected to said other cylinder, said hollow shaft having communication with said cylinders, and means for delivering fluid to said hollow shaft for a first two sets of links pivotally connected to said base member and each set connected to a spacer member, a second two sets of links pivotally connected to said load supporting member and each of said second sets pivotally connected to a spacer member below the pivot points of the first sets of links, a third two sets of links pivotally connected respectively to each of said spacer members, the links of said third sets on one spacer member extending downwardly and pivotally connected to a set of links of the first sets and the other set of said third sets of links extending upwardly from the spacer member and pivotally connected to a set of links of the second sets, one of the sets of links of the second sets connecting a spacer member with said load supporting member and one of the sets of links of the first sets connecting said other spacer member with said base member being of shorter length than the other of said first and second sets of links, and means for delivering fluid to said cylinders for effecting relative movement of said cylinders with respect to said shaft for extending said links for elevating the load supporting member.

PAUL MOENCH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

